JPH03274702A - Printed resistor circuit for trimming - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a printed resistor circuit for trimming used in various electronic devices, particularly hybrid ICs.

(Prior Art) A conventional printed resistor circuit for trimming will be described with reference to FIGS. 9 and 10, taking as an example a case in which a thick film resistor is formed.

FIGS. 9(a) and 9(b) are a plan view and a sectional view taken along the line a-a' of the trimming printed resistance circuit.

In the figure, an insulating substrate 1 is mainly made of alumina or the like, and electrode terminals 2a and 2b are formed by printing and firing a palladium-silver material on its surface, and further, the electrode terminals 2a and 2b are connected to each other. The thick film resistor 3 is formed by printing and firing a ruthenium oxide material. Trimming is performed by using a laser at the center of the thick film resistor 3.
By common means such as sand brackets and cutters,
Insert cutting groove 4. FIG. 10 shows electrode terminals 2a and 2.
It is a resistance value change characteristic diagram between b.

In this manner, the resistance value of the trimming printed resistance circuit can be adjusted by adjusting the depth of the cutting groove 4 of the thick film resistor 3.

(Problem to be Solved by the Invention) However, in the above configuration, the cutting groove 5 indicated by the broken line
If the groove is too deep as shown in the figure, current concentration will occur in the narrow cut remaining portion 6, resulting in a decrease in the stability of the resistance value over time and a decrease in the allowable power, making it difficult to obtain a significant change in the resistance value. . Further, if the thick film resistor 3 is cut by mistake, the resistance value becomes infinite, and depending on the circuit, other parts may be damaged or abnormal operation may occur. Furthermore, as shown in Figure 10, the initial resistance value always starts from a certain value, so in addition to the infinite resistance value at the time of complete cutting mentioned above, the resistance value changes due to trimming, but the general variable resistor There was also the problem that it was not possible to obtain the resistance value change characteristic that can be obtained with a device, and that it was particularly unsatisfactory when applied to functional trimming. Furthermore, since the change in resistance value is not reversible and can only be increased at all times, there is a problem in that it cannot be particularly applied to trimming that requires adjustment of increase or decrease in resistance value.

The present invention solves the above problems, and even if the depth of the cutting groove 5 becomes excessive, the resistance value does not change over time or the allowable power decreases, and even when cut, the resistance value does not become infinite. First, it is an object of the present invention to provide a printed resistor circuit for trimming, which can increase the resistance value from an initial resistance value of approximately zero and can reversibly adjust the characteristic value.

(Means for Solving the Problems) In order to solve the above problems, the present invention forms a rectangular film resistor, four electrode terminals connected to each of its four corners, and connects to one short side of the resistor. Two adjacent electrode terminals are short-circuited with a conductor, the two adjacent electrode terminals on the other short side are used as resistor terminals, and a cutting groove is inserted from the end thereof.

Further, the opposing ends of the electrode terminals for the resistor terminals adjacent to each other at the other end are extended into a right triangle shape and brought into point contact at the center, and the end of the film resistor is aligned on a common line including the contact point, The above contact point is the starting point of the cutting groove.

Furthermore, if necessary, the short-circuited electrode terminals described above may be used as intermediate terminals, and the shape of the cutting groove may be made into a waveform.

(Function) With the above configuration, even if the depth of the cutting groove is too deep,
Since more current is shunted to a conductor with a lower resistance value than the remaining part of the cut, there is no concentration of current in the remaining part of the cut and no reduction in allowable power. Further, even if the film resistor is cut, since it is connected by a conductor, the resistance value will not become infinite, but will show a certain constant value determined by the specifications of the film resistor.

In addition, in a resistor circuit in which the opposing terminal electrodes are right-angled triangles and their vertices are connected, the resistance value gradually increases from zero. It becomes possible to change the value.

Furthermore, since the degree of increase in resistance value between the intermediate terminal and each of the two resistor terminals changes depending on the shape of the cutting groove, by making the shape waveform, each resistor with the intermediate terminal as the midpoint can be The balanced relationship of resistance values between terminals can be adjusted.

(Embodiments) Four embodiments of the present invention will be described with reference to FIGS. 1 to 8.

FIGS. 1(a) and 1(b) are plan views of a thick-film type printed resistor circuit for trimming showing a first embodiment, and FIGS.
FIG. 3 is a sectional view taken along line b'.

In the same figure, this embodiment differs from the conventional example shown in FIG. Bypass electrode terminals 2c and 2 short-circuited by conductor wiring 7
d is formed, and the cutting groove 4 for trimming is inserted from the resistance terminal side. Since the rest is the same as the conventional example, the same components are given the same reference numerals and their explanations will be omitted.

FIG. 2 is a characteristic diagram of resistance value change between the resistor terminal electrode terminals 2a and 2b due to trimming.

In this embodiment, even if the cutting groove 5 shown by the broken line is cut deeply and the resistance value of the cut remaining portion 6 becomes large, the current is more diverted to the conductor arrangement i7, and the cut remaining portion 6
Therefore, it is possible to cut to a range where a more significant change in resistance value can be obtained without causing current concentration or reduction in allowable power.

Moreover, even if the thick film resistor 3 is completely cut, the conductor wiring 7
Since the resistance value is not infinite, the final resistance value is 8, which is determined by the specifications of the thick film resistor 3 and the cut grooves 4.

FIG. 3 is a plan view of a printed resistor circuit for trimming showing a second embodiment. The difference from the first embodiment shown in FIG. The large electrode terminal 2e has a structure that also serves as the electrodes 2c and 2d shown in FIG. 1 and the conductor wiring 7. Since the rest is the same as the first embodiment, the same components are given the same reference numerals and their explanations will be omitted. The resistance value change characteristic due to trimming in this example is that the large electrode terminal 2e is the first
Since it has the same effect as the conductor wiring 7 of the first embodiment shown in the figure, it shows almost the same tendency as the characteristic diagram shown in FIG. is easier than in the first embodiment.

FIGS. 4(a) and 4(b) are plan views showing the state before and after trimming, respectively, of a thick-film trimming printed resistor circuit according to a third embodiment of the present invention.

In FIG. 4(a), this embodiment shows that the first
The difference from the embodiment shown in FIG. This is the point where the right end of No. 3 coincides with the right end of the resistor terminal electrode terminals 2a and 2b. Since the rest is the same as the first embodiment, the same components are given the same reference numerals and their explanations will be omitted.

In FIG. 4(b), during trimming, the cutting groove 4 is
Insert from the contact point 9 at the center of the right end of the thick film resistor 3.

FIG. 5 shows a resistance value change characteristic diagram when such trimming is performed.

Since the resistor terminal electrode terminals 2a and 2b are connected at the contact point 9, the resistance value is almost zero before trimming.
As soon as contact point 9 is broken, the resistance value begins to increase. Further, since the tips of the surface electrode terminals 2a and 2b are triangular, the resistance value increases linearly, and thereafter increases in the same trend as the characteristic curve shown in FIG. 2, reaching a final resistance value of 8. According to this embodiment, in addition to the effects shown in the first embodiment, the resistance value can be increased continuously from zero to the final resistance value of 8, so that the resistance value change characteristic is similar to that of a general variable resistor. is obtained. Note that in the second embodiment shown in FIG.
Of course, if the resistor terminal electrode terminals 2a and 2b have the same structure as in this embodiment, the same resistance value change characteristics as shown in FIG. 5 can be obtained.

FIG. 6 is a plan view of a thick-film printed resistor circuit for trimming showing a fourth embodiment. This embodiment differs from the first embodiment shown in FIG. Wiring pattern 1
0, and the bypass electrode terminals 2c and 2d are used as intermediate terminals, and the cutting groove 4 is bent at the bending points (a), (b), (c), and (b) to form a waveform. . Since the rest is the same as the first embodiment, the same components are given the same reference numerals and their explanations will be omitted.

FIG. 7 is a resistance value change characteristic diagram of the printed resistor circuit for trimming constructed in this way, showing the corner point (A).

The relationship between (b), (c) and (b) and the resistance value between the electrode terminals 2a and 20 and 2b and 2d is that when the wave-shaped cutting groove 4 turns right or left, when it is parallel to the center line, R = R2; As it approaches the electrode terminal 2a side, Rz>R2, and as it approaches the electrode terminal 2b side, it changes so that Rz<R2. Therefore,
According to this embodiment, in addition to the effects obtained in the first embodiment, it is possible to construct a circuit that can arbitrarily adjust the balanced relationship of potentials between the resistor terminal electrode terminals 2a and 2b. FIG. 8 is an equivalent circuit of the fourth embodiment.

In addition, in the second embodiment shown in FIG. 3, the left large electrode terminal 2
In the third embodiment shown in FIG. 4, the conductor wiring 7 is used as the intermediate terminal of each resistor, and the waveform cutting groove 4 is used to obtain the same effect as the present embodiment. can.

Although each of the above-mentioned embodiments is constructed using the thick film resistor 3, similar effects can be obtained by constructing the resistor using a thin film method, a polymer method, or a printed wiring board.

(Effects of the Invention) As explained above, according to the present invention, since the conductor wiring is provided at the end of the cutting groove inserted in the longitudinal direction,
Even if the cutting depth is excessive, current concentration in the cut remaining portion of the film resistor and reduction in allowable power do not occur, and a printed resistor circuit for trimming with a large change in resistance value can be obtained. Therefore, the trimming adjustment range of the resistor is expanded, which is particularly effective in the case of functional trimming.

Furthermore, even if the film resistor is accidentally cut, the resistance value will not become infinite, and other parts will not be damaged or the equipment will not operate abnormally.

In addition, if the electrode terminal for the resistor terminal is triangular, the vertices of both are brought into point contact, and the contact point is disconnected, the resistance value can be increased continuously up to a value of zero, which is different from that of a general variable resistor. Since similar resistance value change characteristics can be obtained, this method is particularly effective for functional trimming.

By using the conductor wiring provided at the end of the cut as the intermediate terminal of the resistor and using the wave-shaped cutting groove, a circuit can be constructed in which the balanced relationship of potential between the two resistor terminals can be arbitrarily adjusted. This makes it possible to reversibly adjust characteristic values, which is especially effective in the case of functional trimming.

[Brief explanation of drawings]

1(a) and (b) are a plan view of a printed resistor circuit for trimming showing an embodiment of the first step of the present invention, and FIG.
2 is a sectional view taken along the line b', FIG. 2 is a resistance value change characteristic diagram, FIG. ) and (b) are both plan views of a printed resistor circuit for trimming showing a third embodiment of the present invention, (a) is a plan view before trimming, and (b)
The figures are a plan view showing the state after trimming, FIG. 5 is a resistance value change characteristic diagram, FIG. 6 is a plan view of a printed resistor circuit for trimming showing the fourth embodiment of the present invention, and FIG. ,
8 is an equivalent circuit diagram of the fourth embodiment, and FIGS. 9(a) and 9(b) are a plan view and a-a' of a conventional printed resistor circuit for trimming. A cross-sectional view taken along the line, FIG. 10, is a resistance value change characteristic diagram when trimming is performed. 1... Insulating substrate, 2a, 2b... Electrode terminal for resistor terminal, 2c, 2d... Electrode terminal for bypass (for intermediate terminal), 2e... Large electrode terminal, 3... Thick film Resistor, 4, 5... Cutting groove, 6... Cutting remainder, 7... Conductor wiring, 8... Final resistance value,
9... Contact point, 10... Wiring pattern.

Claims (4)

[Claims] (1) Two electrode terminals for resistor terminals and two electrode terminals connected to bypass conductor wiring are formed on the surface of the insulating substrate so that each electrode terminal forms a short side of a rectangle. A rectangular film resistor is formed to connect the four electrode terminals, and a cutting groove for trimming is cut in the longitudinal direction from the short side of the resistor terminal. Printed resistance circuit for trimming. (2) A claim characterized in that the two electrodes serving as resistor terminals each have a triangular shape, are connected to each other at one vertex of each triangular electrode, and a cutting groove is formed starting from the contact point. (1) Printed resistance circuit for trimming as described. (3) On the surface of the insulating substrate, two electrode terminals for resistor terminals and one electrode terminal with the same width as the total width of the above two electrode terminals, each forming a short side of a rectangle. A rectangular film resistor is formed to connect the three electrode terminals, and a cutting groove for trimming is cut in the longitudinal direction from the short side of the resistor terminal. A printed resistance circuit for trimming featuring: (4) By using the electrode that was not used as a resistor terminal as the intermediate terminal of the resistor, and making the cut shape of the film resistor waveform, the resistance value between the intermediate terminal and each of the two resistor terminals can be reduced. A printed resistor circuit for trimming that adjusts the balance relationship.